T

type guard

Meet Jane

Less boilerplate. More flow. Zero‑side‑effect normalization and validation helpers for JavaScript.

Jane is a small, clarity‑first helper library for normalizing, validating, and safely parsing unknown input in JavaScript and TypeScript. It’s built for developers who want predictable behavior, composable pipelines, and zero surprises — without schema systems, decorators, or framework lock‑in.

Jane is intentionally small. Intentionally explicit. Intentionally boring in all the right ways.

Build the type guards you want for the supported types you can! And enjoy your compile time errors when you forget to keeping something up to date! ;)